Compression-rheostat.



E. L. CLARK.

COMPRESSION RHEOSTAT.

APPLICATION FILED MAR- 17. I9I3.

2 SHEETS-SHEET 1.

WITNESSES v 0 EMERSOI'IINIIEIKARRK ATTORNEY v v BY g g y COLUMBIA PLANOHRAPH C0., WASHINGTON, D. c.

E. L. CLARK.

COMPRESSION RHEOSTAT.

APPLICATION FILED MAR. 11. 1913.

Patented Sept. 21, 1915.

2 SHEETS-SHEET 2.

INVENTOR EMERSON L.. CLARK BY I WITNES 5 3.

ATTORNEY COLUMBIA PLANOGRAPH 00.. WASHINGTON, D. c

, UNITED srra'rns PATENT OFFICE.

EMERSON CLARK, OF LAKEWOOD, OHIO, AS SIGNOR TO NATIONAL CARBON GOIVlIPANY, F CLEVELAND, OHIO, A CORPORATION OF NEW JERSEY.

COMPRESSION-RHEQSTAT. I

To all whom itma l concern': y 7

Be it known that I, EMERSON L. CLARK, a citizen of the United States, residing at Lakewood, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Compression- 1\ l1BOStfltS, of which the following is a full,

. composed of a number ofsimilar units which may be operated from a single point. Another object is to secure means for transmitting uniform and definite pressure which will not be altered by temperature changes.

Another object is to secure a resistance elementwhich is self-alining.

Another object 'is to obtain a draft or chimney efiect through the rheostat to increase its capacity.

Further ob ect's will appear in the appended description. H I

Referring to"the draw1ngs, Figure 1 is the topplate removed was to show the arrangement of pulleys. Fig. 2 is the front view of the same rheostat'withthe front plate removed. Fig. 3 is a' cross-sectional View of 1 on-the line AA. Fig. 4 is a cross-sectional view of a form of selfalining resistance elements which may be used in the rheostats. Fig.6 is. a crosssectional view of EtIIlQdlfiCEttlOIl of theresistance element shown n F1g.;4;. Fig. 6

'is a cross-sectional view "of another form of self-alining resistance element. Fig. 7

shows the relative position of the grooves in the resistance element to the frame and a compression member. Fig. 8 is asectional I end view of a modification takenion the'line BB' of Fig. 9. Fig. 9 is a partial cross sectional View of the rheostat taken onthe line CC of Fig. 8. Fig. 10 is an enlargedview of a conductingplate used'to connect two piles in series. Fig. 11 is an enlarged view of a conductingp'late used to connect v two piles in parallel. 'Referring to the erly insulated.

weight may be varied so.

\ in parallel by appropriate plates. the top view of a form of my device with v heostat shown inFigs. 1, 2, and 3', aplurality of resistance elements onpl'atesl are'arra-nged "in'a plurality of piles 2. These piles rest on non-conducting Specification of Letters Patent. Patented Se t 21 19 151 Application filed March 17, 1913. serial No. 754,708. 7 I

guide'rods 3 which are supported between the parallel members 4, also of non-conducting material or conducting material prop- The ends of the four members are joined'by end plates 5. Top and bottom plates (3 are preferably secured to the two inner members at to takethe thrust from the piles' Between everyother pile, threaded rods 7 are passed. At one end of each ,rod, pulley blocks 9 are attached to support the pulleys 8. The compression members 10a ht loosely over the other ends of the rods 7 and are held in place by nuts 11. I have shown wheels 12 in the place of nuts llon certain of'the rodsto adjust the rheostat as will be explained later. A cable 13 passes over pulleys15 and 8, and the end 16 is attached to the frame thy the rod 7 and wheel 1.2. Pressure is uniformly" transmitted through the various pulleys by a weight 14: attached to the other end of thecable. The

as to adjust the pressure'as desired. I

The conducting plates 17. are placed as shown to connect the piles in series. Any number of piles, however, may be connected Binding postslS are provided for the terminals. A clamp 19 or other device is fastened to the member 6 so as tohold the weight end of the cable when it is desired to compressth'e rheostat by hand wheel 12. In such case, the weight. of course would have no effect.

' Fig. 10 is'an enlarged'view of the conducting plate 17 This consists of a metal plate having' a notch 21 to fit overjtherod"? and preferably a lug 20 for grasping 'it'to remove it. V

In Fig. 11, a similar plate having two. notches 21 is made long enough to abut against the endsof four piles. Two piles can thus be placed in parallel.

In Figs. 4, 5 and 6, three illustrative types of self-alining resistance elements adaptable for use in" this rheostat are shown. Referringto Fig. 1, the resistanceelementhas a series of parallel corrugations or. grooves 22. The upper surface of the elementzis rounded at 23, the ridges 23 serving as contacts and fitting into the alining grooves 2& inthe adjacent plate. g In Fig. 5 the grooves are "deeper'at one end than at the other.

The resistanceelements would be arranged in the pile so" that the cooling medium wouldente'r'at the shallow arranged in a vertical column.

ously altered.

end of the groove, 2'. 0., in Fig. 2 the shallow end would be at the bottom and in Fig. 8 it would be at the right.

In Fig. 6, a form of element is shown consisting of two differently shaped plates 26 and 27 which embody the same advantages as the elements shown in Figs. 4 and 5. In this figure, the grooves of 27 are made deeper than those of 26 to secure the alining and ventilation features.

In Fig. an enlarged partial cross-section of two piles. and the compression member 10 is shown in order to illustrate the direction of thecorrugations in the rheostat in Figs. 1, 2, and 3. The frame 4 is insulated from the members 7, 9 and 16 as indicated in black in this figure.

InFigs. 8 and 9, the rheostat of Figs. 1, 2, and 3 has been turned to make a vertical insteadof a horizontaltype. Two vertical sides 28 and four members 4 form a frame for the rheostat. The guide rods 3 fit into the members 4 to support the resistance plates 2 infhorizontal rows, the rows being Pressure is applied to the plates by the weight lel through cable 13, and pulleys 15 and 8.

Theresistor plates are placed in this type with the grooves horizontal. A baffle plate 29 sealsthe bottom of the space at the left of the column (Fig. 8) and a similar plate 30Iseals the top of the space at the right.

The cooling medium passes around and between the block as indicated by the arrows. Instead of weights, a variable spring may be used to place tension on the cable 13.

The tension on the cable 13 will tend to draw the pulleys 8 closer together, thus compressing the pilesthrough rods 7 and members 10. It will be noted that the pull on the rods 7 is the same so that the compression in v all the pileswill be equal. Bychanging the tension on the cable 13 by any means, the compression of all the piles 1s simultane- The current will pass through all of the piles in'series on each side of the rheostat when the bridging members of Fig. 10 are placed as shown in Fig. 1. The two sides of the rheostat may be connected either in parallel orin series. The rheostat can be arranged so that two piles are in parallel throughout by using the bridging plate shown in Fig. 11. Similarly, three piles couldbe placed in parallel by using connectors spanning six piles. Piles connected in paral'lel ivill carry the same load, since they are all equally compressed.

Theqresistance of thebank of resistors maybe adjusted by changing the weights previously described. lVhen the weight is used, the compression is independent of the expansion or contraction due to change of temperature.

By locking the cable 13 by means of the clamp 19, the action of the weight will be removed and the compression of the piles can be varied by means of any one of the hand wheels 12. The whole rheostat can thus be uniformly controlled at one point.

In Figs. 1 and 2, I have shown set screws 31 threaded into the member 4 to engage two of the rods. 13y tightening these set screws, the rods 7 and pulleys attached thereto will be held stationary. In"this manner, the resistance of the piles controlled by the two rods may be regulated independently of the others by adjusting the hand wheels or nuts connected thereto. Similar screws of course can be used to hold any or all of the rods 7. Sometimes it is necessary to have a constant resistance with translating devices connected in shunt thereto. lVithmy device the piles controlled by therods held by the screws 31 may be connected for instance across the line and translating device may be tapped off of one of them, and the remaining ones may be connected in series therewith to regulate the current.

In the type of rheostat shown in Figs. 1, 2 and 3, the air will pass vertically through the grooves in the resistor plates and absorb the heat generated. The sides 5 of the rheostat extend above and below the piles and thus produce a chimney effect. These sides may be extended to any height desired.

The grooves in the back of the plates shown in Figs. 4 and 5 serve as means for keeping them in alinement; hence, no plates.

or rods are needed at the sides of the pile. This is an important feature as friction is thereby reduced which makes the pressure between allthe blocks more uniform.

In the rheostat shown Figs. 8 and 9, the arrangement of pulleys and weights is similarto that of Figs. 1, 2 and Instead of arrangingthe plates with the grooves vertically so that the heated air from one plate would pass into the next they are placed with the grooves horizontal. .A lower bafl'le 29 permits air to enter at one side only. A baflle .30 is placed diagonally opposite'at the top and prevents the air from leaving at the same side'on which it enters, thus forcing the air to pass horizontally through the grooves and between the piles, as shown by the arrows. The heated column of air in the rheostat will cause a considerable draft which will aid in'the ventilation. Any of the plates shown in Figs. 4 and 5, and (5 could be used in this vertical type, with the same advantages as previously described.

The location of theweights and pulleys in the preceding figures is not by any means the only one which could be used. Many other variations of the arrangement may be readily devised. Likewise, other forms of plates and alining means could be used to accomplish the same results as those specifi' I cally shown.

Having described my invention, What 'I' claim is:

1. Ina compression rheostat, a plurality of piles, rods for transmitting pressure to said piles and flexible means cooperating With said rods to compress the piles.

2. In a compression rheostat, a plurality of .piles, means for transmitting pressure thereto, and aflexible cable forlapplying force to said means.

,3. In a compression rheostat, a plurality of resistance elements arranged in a plurality of piles, compression members, rods connected to said members, pulleys secured to the rods, and flexible means passing. around the pulleys for'compressing the piles.

4. In a compression rheostat, a plurality of resistance elements arranged in a plurality of piles, compression members and flexible means attached to the said compression members to simultaneously compress the piles.

of corrugations on one side and alining grooves on the other, said corrugations vary- .ing in depth from one end to the other.

6. A resistor having a plurality of corrugations, each of said corrugations varying in depth from one of its ends to the other.

7. A resistor having. corrugations varying in depth from one of their ends to the other.

A resistance element having a plurality- 8. A corrugated resistor plate having the top of the ridges parallel to the plane of the base of the plate and having said corrugations of variable depth.

9. In a compression rheostat, resistor plates having upper and lower bounding planes, a plurality of adjacent grooves in each plane, the grooves in one planevarying in depth from one of their ends to the other, and the ridges in one plate adapted to fit into the grooves of the adjacent plate to aline the said plates.

10. In a compression rheostat a plurality of corrugated resistors, a plurality of piles consisting of said resistors arranged vertically, and means for admittinga cooling medium at one side only of the corrugations, and Withdrawing it at the other side.

11. In a compression rheostat, a plurality ofcorrugated resistors having the corrugations in'a horizontal direction, a plurality of piles consisting of said resistors arranged vertically, and means for admitting a'cooling medium at one side only of the corrugations and Withdrawing it at the other side.

In testimony whereof, I hereunto afliX my signature.

EMERSON L. CLARK. Witnesses:

IRA J. ADAMs, II. Gr. Gnovnn.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

. Washington, D. C. p 

